What country has the entrepreneurship, technology and defense capability Canada needs? America.

Has the time come to face the music and dance? Yes, says Diane Francis, editor-at-large at the National Post in Toronto. Her book “Merger of the Century: Why Canada and America Should Become One Country” is both provocative and persuasive.

“The genius of both societies is that they are very good at assimilating people from all over the world,” Francis told me. “So why can’t they do it themselves?”

Relatively small differences are why. Canadian intellectuals have long portrayed the United States as their violent, unruly twin. Many conservatives in this country, meanwhile, deride Canada as the socialistic land of single-payer medicine, gun control and other heavy regulation.

“I don’t buy the narrative of American exceptionalism or Canadian superiority,” says Francis, a dual citizen (born in Chicago). “Both have good points and bad points.”

Americans close to the border already think a lot like Canadians, she notes. Some northern states actually have more liberal laws and lower crime rates than Canada’s. “They are more Canadian than Canadians.”

But set aside these “local” considerations. There’s a big, scary reason the countries should merge: to create a united front against outside aggressors, especially China and Russia. These countries’ sights are set on Canada’s rich and poorly defended open spaces.

“Neither nation upholds the same values as Canadians or Americans,” Francis writes, “and they represent Trojan horses that are eager to partition an already weak, fragmented Canada.”

She goes on: “China has targeted Canada for years because of its enormous oil sands, its undeveloped resources, its dominant Arctic position, its backdoor entry into the U.S. market and technology sector, and its vast landmass capable of supporting millions more people.”

For example, China’s state-run oil company was able to buy Nexen, the Canadian oil giant, for $15 billion despite loud public opposition and warnings by Canadian intelligence. China got a trade deal giving it special market access for 31 years, while Canadians are still banned from buying China’s iconic corporations.

Meanwhile, the melting Arctic is exposing massive resources. Canadian blood pressure rose when Russian explorer Artur Chilingarov announced, “The Arctic is Russian” and then his sub planted a Russian flag on the seabed.

Canada can hardly defend its territory in an age of resource grabbing while ranking 14th in military spending and 74th in military manpower. Only the United States can do that, which, of course, it’s been doing all along. Americans are tiring of providing free rides to other countries.

The United States and Canada could reach the altar by several paths. One would start with a single currency, move to a customs union and end at political union. Europe is already at monetary union. “The countries have different health care systems, different taxes, but there’s no border.”

What does each partner have to offer? “Canada’s best assets include its resources, stability and banking system, its strong relationship with the United States and an educated, law-abiding people,” according to Francis.

America offers a culture of risk taking and entrepreneurship. It leads the world in technology and defense.

“There’s no excuse for two countries as similar as us to not get rid of the border after 26 years of free trade,” Francis says.

A merged Canada and U.S. would occupy more land than Russia or all of South America. It would become an energy and economic powerhouse less subject to foreign intrigue.